1. Field of the Invention
The present invention relates to novel oxygen-containing organic sulfur compounds, methods of preparing such compounds and methods of using the compounds as polymer chain length terminating agents.
2. Description of the Prior Art
In the synthesis of a polymer from monomer reactants, the average chain length, and hence the average molecular weight, has heretofore been controlled at a desired level by combining a chain length terminating agent with the reaction mixture during the course of the reaction. The chain length terminating agent is a compound which is more reactive than the monomer reactants, but which does not self-polymerize or copolymerize with the monomers. When introduced into the polymer synthesis reaction mixture, the chain length terminating agent preferentially reacts with the then-existent polymer chains to cause the termination of additional chain growth. Heretofore unavailable highly reactive oxygen-containing organic sulfur compounds are particularly suitable as polymer chain length terminating agents.
The preparation of organic sulfur compounds by reacting hydrogen sulfide with organic compounds containing ethylenic linkages has heretofore been known in the art. For example, U.S. Pat. No. 3,050,452, issued Aug. 21, 1962, describes the preparation of organic sulfur compounds such as mercaptans and thio-ethers by reacting an ethylenically unsaturated compound with hydrogen sulfide in the presence of ultraviolet radiation and a trialkyl phosphite promoter.
By the present invention novel oxa-organic sulfur compounds, methods of preparing such compounds and methods of using the compounds as polymer chain length terminating agents are provided.